Life-time extension of alumina forming FeCrAl–RE alloys: influence of alloy thickness

Abstract

Oxidation lifetimes of the FeCrAl–RE alloys at ultra high temperatures are governed ultimately by chemical failure of the protective alumina scale, often accelerated by prior mechanical failure resulting in scale cracking and spallation. Critical parameters involved in these failure modes are expected to be influenced by alloy thickness. Therefore, the effect of alloy thickness upon the lifetime oxidation behaviour, in air, at 1,300°C has been studied for three commercial FeCrAl-RE alloys, Kanthal AF, Kanthal APM and PM2000, that have been fabricated by the three principal fabrication routes. As a result, these alloys have different creep properties, which also could have a significant influence on oxidation behaviour.